The objectives of this research are: a) to discover all the enzymes that participate in RNA degradation in Escherichia coli; b) to find out all the structural and regulatory genes that govern these enzymes; c) to understand the mechanism of mRNA degradation, stable RNA maturation (which involves degradation), and stable RNA degradation during starvation. These objectives will be aimed at by (1) identifying unknown ribonucleases; (2) isolating bacterial strains defective in known and as yet unknown ribonucleases; (3) analyzing genetically these ribonuclease mutations (location, dominance, recessivity, etc.); (4) studying the effect of the mutations in vivo for instance, on macromolecule synthesis and half-life of mRNAs and in vitro in a cell free system where transcription and translation occur simultaneously.